The present invention relates to a disc drive storage system. In particular, the present invention relates to a swaging device for coupling a suspension system supporting a head gimbal assembly relative to an actuator arm.
Disc drives are well-known in the industry. Disc drives are used to store digital information on rigid discs coated with a magnetizable material in a plurality of circular, concentric data tracks. Discs are mounted on a spindle motor which rotate the discs for operation. Information is read from or written to the disc surface via transducers carried on a slider supported relative to the disc surface via a suspension system.
The suspension assembly includes a load beam and a gimbal spring for supporting the slider. The slider is coupled to the gimbal spring at an upper surface of the slider. The gimbal spring is also coupled to the load beam. The lower surface of the slider defines an air bearing surface. Rotation of a disc via the spindle motor interacts with the air bearing surface of the slider to create a hydrodynamic lifting force to lift the slider to fly above the disc surface for reading information from and writing information to the disc surface. The gimbal spring supports the slider to allow the slider to pitch and roll relative to the disc surface for operation. The load beam supplies a preload force to counteract the hydrodynamic lifting force of the slider. The preload force supplied by the load beam and the hydrodynamic lifting force created by the air bearing surface and rotation of the disc define the fly characteristics of the slider (and transducers) above the disc surface.
The slider is positioned relative to various concentric data tracks via an actuator mechanism. The actuator mechanism typically includes an xe2x80x9cE-blockxe2x80x9d assembly, which is rotationally coupled to a base of the disc drive to define a rotary-type actuator. The E-block includes a plurality of spaced actuator arms and is rotationally operated via an actuator drive under the control of electronic circuitry. In particular, the suspension assemblies supporting the sliders are coupled to actuator arms of an E-block in alignment with upper and lower surfaces of discs supported by the spindle motor.
The suspension assemblies are coupled to the actuator arms via a swaging technique. The suspension assemblies include a tubular-shaped stake having an opened central channel extending therethrough. The outer dimension of the stake is sized for insertion into a hole extending through an actuator arm of the E-block. After the stake is inserted into the hole, the stake is swaged to the hole of the actuator arm via the central channel to secure the suspension assembly to the actuator arm.
Typically, suspension assemblies are coupled to opposed surfaces of an actuator arm for alignment relative to lower and upper disc surfaces. In particular, a tubular-shaped stake of a first suspension assembly is inserted into an upper portion of the hole such that extended ends of the stake extend downwardly from a fixed end. The stake is coupled to the upper portion of the hole for alignment relative to an upper disc surface. A stake of a second suspension system is inserted into a lower portion of the hole such that extended ends of the stake extend upwardly from a fixed end. The stake is coupled to the lower portion of the hole for alignment relative to a lower disc surface. A swaging device is inserted through the central channel of stakes positioned in the hole to impart a swaging force to deform the stakes against a wall of the hole for permanently connecting suspension assemblies to actuator arms.
Fixed diameter swaging ball devices are known for deforming or pressing stakes into the hole of the actuator arm to connect the suspension assemblies. The diameter of the ball is sized larger than the diameter of the channel to impart a swaging force to the stakes. The swaging ball is typically inserted in a single direction to swage both stakes position in upper and lower portions of the hole. For example, the swaging ball is initially inserted through the first stake at the upper portion of the hole. Due to the alignment of the first stake and insertion direction of the swaging ball, the swaging ball is inserted into the stake channel at the fixed end of the stake and exits at the extended end of the stake. Thus, the swaging ball supplies a tension force to the stake which may increase the preload force of the suspension assembly.
Thereafter, the swaging ball is inserted through the stake at the lower portion of the hole. Due to the alignment of the second stake and insertion direction of the swaging ball, the swaging ball is inserted into the stake channel at the extended end of the stake and advanced along the channel to exit at the fixed end of the stake. Thus the swaging ball supplies a compressive force to the stake which may decrease the preload force of the suspension assembly. Thus, as described, different preload characteristics are introduced by known fixed-diameter swaging devices to suspension assemblies aligned with upper and lower disc surfaces.
The stressing forces described influence the flying characteristics of the slider and have a greater impact or influence on the fly characteristics of smaller and lighter suspension assemblies which require less preload force in the flexure to fly at a correct height. Since the first and second suspension assemblies have different preloads supplied during assembly, each has different fly characteristics. It is desirable to reduce variations in preload characteristics introduced during assembly so that consistent fly characteristics may be provided for each data head for operation of the disc drive. The present invention provides a solution to this and other problems, and offers other advantages over the prior art.
The present invention relates to a swaging device for connecting suspension assemblies to actuator arms of a disc drive. Suspension assemblies may be coupled to actuator arms by tubular stakes extending from a mounting plate of the suspension assembly. The tubular stake is inserted into a hole extending into the actuator arm. The tubular stake is swaged by a swaging device to secure the tubular stake within the hole.
The swaging device of the present invention includes an expandable member which is expandable between an insertion dimension and a swaging dimension. In the insertion dimension, the expandable member is sized for insertion into a channel of a tubular stake. The expandable member is expanded to the swaging dimension to impart a swaging force to the tubular stake to swage the tubular stake relative to the hole of the actuator arm. Features and advantages which characterize the present invention will be apparent upon reading of the following detailed description and review of the associated drawings.